<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        *{
            margin: 0;
            padding: 0;
            outline: 0; 
            /* input a button img 
            ios android 移动款 wekit 统一了
            浏览器轮廓不统一 webkit(开源内核) chrome(商业) 
            ie */
        }
        body{
            color: #111;
        }
        a{
            text-decoration: none;
            color: inherit;/*继承*/
        }
        .pj_tabbar{
            display: flex;
        }
        .pj_tababbar__item{
            flex: 1;
            height: 50px;
            border-bottom: 1px solid #ddd;
        }
        .pj_tababbar__item a{
            display: block;
            line-height: 50px;
            text-align: center;
        }
        .pj_tababbar__item a:first-child{
            border-right: 1px solid #ddd;
        }
        .pj_tababbar__item_on{
            background-color: pink;
            color: white;
        }
    </style>
</head>
<body>
    <!-- 手感 -->
    <div class="pj_tabbar">
        <div class="pj_tababbar__item pj_tababbar__item_on">
            <a href="#" data-type="basic">
                basic
            </a>
        </div>
        <div class="pj_tababbar__item">
            <a href="#"  data-type="super">
                super
            </a>
        </div>
    </div>
    <div id="list">

    </div>
    <script>
        const list=document.getElementById('list');
        const links=document.querySelectorAll('.pj_tababbar__item a');
        // const tabTypes={
        //     basic:Symbol(),/*es6里新的简单数据类型，独一无二*/
        //     super:Symbol()
        // }
        // java等大型语言，tab切换时，为了可读性 tabTypes对象常量
        // 所有tab类型的管理 统一
        const tabTypes={
            basic:'basic',
            super:'super',
        }
        links.forEach(link=>{
            link.addEventListener('click',function(event){
                // a 带来交互感觉
                event.preventDefault();
                const type=event.target.dataset.type;
                const parent=this.parentNode;
                // console.log("parent");
                if(!parent.classList.contains('pj_tababbar__item_on')){/*包含*/
                    document.querySelector('.pj_tababbar__item_on')
                        .classList.remove('pj_tababbar__item_on')
                    parent.classList.add('pj_tababbar__item_on');
                }
                console.log(type,tabTypes.basic);
                // if(type=='basic'){
                if(type==tabTypes.basic){
                    console.log('----------');
                    list.innerText='basic';
                }
                if(type==tabTypes.super){
                    console.log('++++++++++');
                    list.innerText='super';
                }
            });
        })
    </script>
</body>
</html>